Anomalous deep ion-induced modification of HOPG

Effects of the deep ion-induced modification of highly oriented pyrolytic graphite

“…The observed differences in the γ(Т) dependences measured in heat ing and cooling our HOPG samples indicated that the dynamic equilibrium conditions were not fulfilled and the formation of a thick altered layer is possible during irradiation. This evidence was corroborated in later studies conducted using Rutherford backscattering spectrometry [12,13].…”

“…Irradiation was performed on the mass monochro mator setup at the Skobel'tsyn Institute of Nuclear Physics using Ar + ions with energies ranging from 10 to 30 keV and fluences ϕt ~ 10 18 -10 19 ion/cm 2 , follow ing the procedure outlined in [12,13]. HOPG (UPV 1T) samples in the form of plates with the (001) base plane were used in our experiments.…”

“…For example, studies of an altered surface layer of HOPG (UPV 1T grade) conducted by backscattering spectrometry [12,13] showed that irra diation with argon ions with energies on the order of tens of kiloelectronvolts can (at certain temperatures of the target) result in significant structural and mor phological changes at depths an order of magnitude greater than the projected range of ions within the target. The threshold character (with respect to energy) of these effects in the deep modification of the surface of HOPG at high ion irradiation fluences suggests the presence of threshold radiation damage levels [13][14][15].…”

Relief evolution of HOPG under high-fluence 30keV argon ion irradiation

“…Three of them obtained at the temperatures 90, 250, and 400°C and characterized with different reliefs were selected for this work to investigate UPV-1T sputtering. Some description of the ion-induced UPV-1T-surface changes at a fluence of $10 18 ion/cm 2 has been presented in [18,29]. The initial mirror surface of the UPV-1T remains relatively smooth only upon ion irradiation at temperatures lower than that of the ion-induced texture transitions T t % 150°C (Fig.…”

“…Its mosaic structure is characterized by axis texture in the [0 0 1] direction normal to the plate surface; disorientation of the basal planes does not exceed 50 0 . The pronounced effect of temperature on ion-induced structural, emission, and morphological changes different from the respective ones for polycrystalline graphites is observed for HOPG upon high-fluence ion irradiation with Ar + and N 2 + ions with energies of tens of keV [3,4,[13][14][15][16][17][18]. In particular, it has been found that the sputtering yield is practically twofold lower upon sputtering of the basal plane of UPV-1T with 30-keV Ar + ions in comparison with Y values upon the sputtering of polycrystalline graphites in a wide range of ion incidence angles [17].…”